


a broken throne

by AwakeAndAliveSpartan



Category: Ao no Exorcist | Blue Exorcist
Genre: Future Fic, Gen, In a way, One-Shot
Language: English
Status: Completed
Published: 2020-07-05
Updated: 2020-07-05
Packaged: 2021-03-04 21:40:30
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,580
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25093246
Author URL: https://archiveofourown.org/users/AwakeAndAliveSpartan/pseuds/AwakeAndAliveSpartan
Summary: When Mephisto shows Rin what has become of the world in the future, Rin becomes determined.Determined to save Yukio before it's too late.
Relationships: Okumura Rin & Okumura Yukio
Kudos: 33





	a broken throne

(Sometime in the Future)

Rin awoke to see a blackened sky above him, the stench of sulfur in the air. He groaned as he peeled himself off of the ground, his stomach flipped as he saw his surroundings. It looked like Kyoto, maybe. Everything was twisted and burned, the hollowed-out shells of buildings looming above him, demons flyings through the blackened air. His face fell as he saw Kyoto Tower, now nothing more than a burning spire of blue flame. 

“What?”

“Ah, good, you’re awake.”

Rin spun to see that familiar white terrier trotting up to him, his fur a stark contrast against the hellscape around them. “Mephisto?” He pointed to Kyoto Tower, “What the hell is this?”

“Exactly.” Mephisto stayed in dog form, which was strange to Rin. “But, this is Kyoto. Assiah and Gehenna at the very same time. A demon sits upon a throne in the Tower, twisted to his demented yearnings.” There was a hint of amusement in the demon’s voice. Something that Rin didn’t like.

“But, this isn’t the present.” Mephisto continued. “This is 2016, five years into the future. I brought you here as a warning, Mr. Okumura. This is what will be if things aren’t stopped. If the Gehenna Gate isn’t sealed.”

Rin’s tail bristled behind him, “You’re a Demon King, right? Why didn’t you stop something like this?” he asked. He brushed ash off of his uniform. 

Mephisto let out a ‘tsk’ sound. “Unfortunately, it isn’t as simple as that. This future surrounds you, Mr. Okumura.” he began to explain, trotting ahead towards the tower, motioning for Rin to follow him. “It is something that I cannot intervene with because of Father. But, I believe that it’s something that you can stop. I don’t think it’s too late yet, but I wanted to show you what hangs in the balance if things aren’t changed.”

Rin swallowed as he followed the ‘dog’, “So, what happened?” he asked, grimacing as he heard a demon screech from somewhere far off in the distance.

“We failed to close and seal the broken Gate. Demons spilled out into the world, cutting humanity by half. Assiah and Gehenna soon melted together, creating  _ New Gehenna _ . But, your father is long gone, long destroyed by the melding of dimensions.”

Rin paused and turned to look at the Demon King, “What?” Everything was too much for him to process right now. 

Mephisto let out a dark chuckle, “You will see soon enough, Mr. Okumura. May this be the  _ motivation  _ you need to change things.” A bright light suddenly enveloped the two of them and when the light subsided, Rin found that they were in the observation deck of Kyoto Tower.

Or what used to be the observation deck.

It had been twisted and reformed into a throne room, blue hellfire burning in just about every crevice. An obscured figure sat upon a throne, an unformed figure being forced to kneel by naiads in front of the figure. Two bariyons weighed his legs down so he couldn’t escape. It looked like some kind of sick torture game. 

“Who is that?”

Mephisto jumped up on a pillar, still in his dog form,“I present to you the crown prince of Gehenna.” he announced. “Don’t worry, he can’t see us. I have us in a separate area of space. We are only able to observe.”

Rin’s stomach dropped, “Crown prince of Gehenna?” He tried to get a better view of the obscured figure. He had a fear of who it was. A hunch of sorts. But, he would be proven wrong.“It… It isn’t me, is it?”

“No. Just wait and you will see.”

“So,” a voice boomed as the figure rose to his feet. Two koks suddenly appeared by his side. Rin still couldn’t make out who it was, but he could tell the figure had two massive horns that arched over his head. Almost like a crown. “Tell me why I should spare you. The True Cross is the enemy of my empire, you know. I should kill you right where you kneel.”

He stepped forward and Rin felt all the oxygen escape his lungs. No, this couldn’t be happening. This couldn’t… That couldn't be _him_ , could it? 

“ _ Yukio? _ ” 

Mephisto let out an amused laugh, “Surprised?” he asked. “That is your brother and not your brother at the same time.”

Rin didn’t respond, he couldn’t tear his eyes off of Yukio. He still seemed to be dressed in an Illuminati uniform, but it looked closer to Lucifer’s than he old one. Blue flames poured from his eyes and Rin could see that his hair had turned pitch black and it was styled into a spiky undercut of sorts. A long tail flicked behind him. His demon heart shone brightly with hellfire on his chest, but the heart itself was as dark as night and twisted and mutated with thorns. Yukio’s glasses were long gone and as he smiled, Rin could see a mouth full of razor sharp teeth.

It was like Yukio’s demon form was a stark contrast to his own. 

They really were Yin and Yang. Two sides of the same coin.

“The Gehenna Gate caused Father and our brother to merge into one being since Father was occupying his eye. Forced possession in a way..” Mephisto explained, not waiting for Rin to ask. “He is your brother, but twisted by Satan’s mutation. In fact, he  _ is  _ the new Satan. The Antichrist of sorts. Funny how everyone thought it would be you, but it ended up being your brother in the end. This was something that I did not foresee, unfortunately. For some things are even out of my sight.”

“I destroyed the True Cross when I took over the Illuminati.” Yukio continued, approaching the frightened exorcist with a sneer on his face. “With Lucifer killed, that gave me room with what I wanted to do. I was never loyal to Lucifer’s cause. The Illuminati was only a means to an end. I wanted the True Cross gone for what they did to me. What they did to my father.” Rin knew that he didn’t mean Satan. “It was time for them to burn to the ground and the Illuminati was the only option that I had.”

Rin looked to Mephisto for an answer.

“Well, you already know that your brother hates the True Cross. But, becoming the new Satan made that hatred worse. It took his hatred and twisted it into something rather monstrous. He sought for a way to completely destroy them and he found that by overtaking the Illuminati and killing Lucifer. Lucifer’s death is what destroyed the majority of the world and the new Satan’s influence twisted it back into a hellscape. A good portion of humanity managed to survive, but now they live under his reign. Funny how things work, isn’t it?”

“How did this happen?” Rin croaked, trying to tune “Yukio” out. He couldn’t bear to watch anymore.

“When he fled after your fight, he lost himself. That allowed Father to meld with him when the Gate twisted the world.” Mephisto kept his eyes on the scene as the exorcist begged for his life. “That is what must be changed, Mr. Okumura. You and the Exwires must find him and convince him to come home before it’s too late. I’ll try to hold off the Gate with the Grigori as long as I can. But, I cannot hold it forever since it has already broken.”

Rin’s eyes widened as “Yukio” pointed at the exorcist. “Naiads, Naiad’s Carousel. Drown him.” he ordered. “I do not feel like arguing with this man any longer.”

Rin’s knees buckled as a water sphere surrounded the man, cutting off his screams as he began to drown. “Mephisto, send me back. Please.” he begged. “I can’t see this any longer. Please.”

“Gladly.”

The light enveloped them again and Rin found himself in Mephisto’s office back at True Cross Academy. He was still trying to process the Yukio that he had seen. No, the  _ monster _ he had seen. That wasn’t his brother. His brother had been long gone at that point.

“So, that’s really going to happen?” 

Mephisto, now in normal form and sitting at his desk, looked up, steepling his fingers, “If things keep going the way they are going, then yes. That is the future that befalls Assiah, unfortunately. And I don’t think that you would even want to know what happened to you at the hands of your “brother”, do you?”

Rin didn’t look at him, “No.”

“There’s still a chance, Mr. Okumura.” Mephisto continued. “That doesn’t have to happen. All you have to do is manage to convince him that this is his “home”. I don’t care if he likes me or not, but I believe that you and the Exwires are the closest thing he has to a family at this point. You need to step up and bring him back before it’s too late.”

Rin remained silent for a bit, unsure of what to do. Yes, he wanted to bring Yukio home, more so now that he knew that doing so would prevent an apocalyptic future. But, Yukio was stubborn and was convinced that he didn’t need saving. Yukio would fight tooth and nail to prove that he was strong. That he didn’t need to be saved.

But, there was nothing Rin wouldn’t do for his brother. 

Especially when the future of Assiah was at stake. 

**Author's Note:**

> Unfortunately, I plan on this only being a one-off quick oneshot and nothing else. I'm too busy with other fics for another fandom for this to turn into anything major. But, nonetheless, I hope that you enjoyed! Find me on Twitter @hellfxres!


End file.
